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What is the difference between concurrency and parallelism?
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Concurrency is when two or more tasks can start, run, and complete in overlapping time periods. It doesn't necessarily mean they'll ever both be running at the same instant. For example, multitasking on a single-core machine.
Parallelism is when tasks literally run at the same ti...
What are good alternatives to SQL (the language)? [closed]
...h is now called Slick) and rewrote the entire system and every 6 queries become 1, just because you could encapsulate and have local methods! If anyone is suffering from SQL horrors, look up Scala Slick or Quill and prepare for enlightenment!
– ChoppyTheLumberjack
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Multiple inheritance/prototypes in JavaScript
I've come to a point where I need to have some sort of rudimentary multiple inheritance happening in JavaScript. (I'm not here to discuss whether this is a good idea or not, so please kindly keep those comments to yourself.)
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What's the best way to put a c-struct in an NSArray?
...ort CoreGraphics structures – you can use it for your own too. I would recommend doing so, as the class is probably lighter weight than NSData for simple data structures.
Simply use an expression like the following:
[NSValue valueWithBytes:&p objCType:@encode(Megapoint)];
And to get the va...
Regular expression that matches valid IPv6 addresses
...lar expression that matches valid IPv6 addresses, including those in their compressed form (with :: or leading zeros omitted from each byte pair).
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Declaring variables inside or outside of a loop
...laring it inside the while loop would not be an option, since it would not compile.
So, since str is not used outside the loop, the smallest possible scope for str is within the while loop.
So, the answer is emphatically that str absolutely ought to be declared within the while loop. No ifs, no an...
Delete multiple records using REST
...ind out if your request has been accepted, rejected, is in progress or has completed. This is useful for long-running operations. Another way is to send a PATCH request to the list resource, /records, the body of which contains a list of resources and actions to perform on those resources (in whatev...
Why are private fields private to the type, not the instance?
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I think one reason it works this way is because access modifiers work at compile time. As such, determining whether or not a given object is also the current object isn't easy to do. For example, consider this code:
public class Foo
{
private int bar;
public void Baz(Foo other)
{
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How many threads is too many?
...rocessing of requests as they arrive as you need to wait for a thread to become available.
That's why you measure. As you state, the vast majority of your threads will be waiting for a response from the database so they won't be running. There are two factors that affect how many threads you should...
Generate a random point within a circle (uniformly)
...a distance x+y from the origin. If x+y>R we fold back down.
Here's the complete algorithm for R=1. I hope you agree it's pretty simple. It uses trig, but you can give a guarantee on how long it'll take, and how many random() calls it needs, unlike rejection sampling.
t = 2*pi*random()
u = rando...